The true northerner. [volume] (Paw Paw, Mich.) 1855-1920, 1887-07-13
STUDYING THE TORNADO.
Appalling Losses or Life and Property
During the Last Two Hundred
Years.
The Mississippi Valley the Region of
Greatest Violence-Mountain
Districts Exempt.
Washington special

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property by tornadoes at this season
causes much fear in several States. Re-
cent Investigations by Lieut.. John p.
Finley, Signal Service United States
army, reveal to some extent the danger
in each region, which will do much TO
allay unnecessary alarm in the Eastern
States. At the same time other re-
gions before thought to be compare
lively safe are found to be more dan
gerous than had been supposed.
The first striking result Of the exam
ination of Lieut.. Finley's map showing
the geographical distribution of 1867
tornadoes from 1862 to 1856, in
elusive, is that they uniformly
avoid extended mountain ranges.
The Rocky Mountains present
so insurmountable a barrier that
the country lying west of this great
range is almost entirely free from the
long violent tornado tracts seen in Kan
sas and Missouri. 1t is known that
storm -centers which form west of the
Rocky Mountains are imperfectly de-
veloped, and are not persistent or vio-
lent in their course until the Nissis-
sippi valley is reached. Tomatoes
form at AN average distance of 453
miles southeast of the main storm
center, as shown in Al cases c.ted by
Prof. II. A. Hazen, of the signal SER
vice. 1t follows that the cold air from
the foot of the Rocky Mountains, COM
ing in the wake of an eastwardly NOV
ing storm, manifesting unusually low
barometer, causes sharp contrasts of
temperature in Kansas and Mis-
souri,, and these contrasts, sometimes
as much as 80 degrees, result in great
tornadoes frequently in Northwestern
Missouri and Northern Kansas. It is
further shown by the distribution of
tornado tracts that the average of
severity and destruction steadily lessons
as the storm centers move eastward
from the Mississippi Valley. This wan
ing OF tornado power is gradual, but
the danger does not entirely cease as
the Atlantic coast is approached. The
coast lines of the Gulf of Mexico and
of the Atlantic Ocean are nearly free
from tornadoes, because great contrasts
accompanying storm centers can not
develop, owing to the equalizing effect
of the ocean temperature and
moisture. OF the total number of
tornadoes reported nearly one-half
occur in the Mississippi Valley,
which is the region of greatest violence.
The lapse of time must max. this even
more marked, because the records of
the Eastern States cover a much long
er period, while the number of lorna
does is less. The region of greatest
frequency is along the north and west
boundary lines of Missouri, increasing
toward the point of intersection. Then
comes Northwestern Georgia, extend
ing into Alabama. 4 very solid and
compact region of tornado develop
ment is in Southern Michigan, tending
toward the lower part of Lake Michi-
gan. For distance of about 200 miles
square this region nearly equals that of
Kansas in frequency, though it has not
more than one-tenth its extent, and its
average severity far less. In the
Eastern States the most remarkable
region next to Western New York is
in the Connecticut River valley, which
seems to be persistently followed by
tornadoes through Connecticut and
Massachusetts, into New Hampshire.
The open country here favors the de-
velopment of q small tornado with a
track about mile or half mile long
and from two TO five hundred feet in
width. Western Connecticut and Massa-
chusetts favor the accumulation of
warm air from the Southwest,
which moves steadily northward,
while Pennsylvania, Virginia and
Western Delaware remain cool,
this causing sharp contrasts of
temperature. In southeastern Penn
sylvania neag the bend of the Del
aware River there is a group of lorna
does centering near Trenton, y. j.
Southeast of Lakes Erie and Ontario
there is also lively region which is an
extension due to the still higher con-
trasts of temperature common in the
Mississippi Valley and southern Mich
igan. In northeastern Mississippi
there is very marked extension of the
Georgia and Alabama region. thong b
not equaling it in frequency.
The value of property reported to
the Signal Service as destroyed in 205
years was about So, 900, 600. leu
tenant Finley estimates this to be about
one-tenth the actual value, making the
total losses about $500, 600, 900. The
number of deaths reported was 3, 165,
and the injured, 5.0i9. These figures
are doubtless much below the actual
damage, because tornado reports in
clude the main facts only. The trans
mission of news is partly INSTRUCTED,
and isolated regions escape report.
The comparison of a number of tor
nadoes with the amount of forest land
by Safes, according to the United
States census, indicates that these
storms are not appreciably influenced
by the presence or absence of forests.
Tornadoes are caused 10y the persist
ent movement and accumulation of air
masses on an immense scale. Forests
and OF her local features of landscape
have little effect.
The signal service reported $50 tor
nadoes for 1886, 1916 for 1885, 200 for
1884, 16l for 1eS9, and from that time
back to 1870 the number diminishes to
Q. This does not represent change
in the actual number, but only indi-
Gates additional facilities for observa-
ton, due to the steadily increasing n
terest taken by the press and people,
as we'll as TO the organization of large
etaff of voluntary tornoIo ranortara a,